A keychain-sized device capable of teleporting any chosen thing to your specified destination.
Take a moment to think about how incredibly amazing this is: someone you really want to see writhe in pain? Teleport a Japanese giant hornet directly into his or her eye socket! In a pinch? Send your intended victim straight into the centre of the sun! Bored on a sunday afternoon and want some laughs? Summon a lifesize model of a horse to a point exactly 100 feet above someone who annoys you! Or just simply late for work? Uh oh, must have missed the alarm, I'll just use my device to teleport myself straight to the office this morning. Oh crud, the boss is on your case! Well now he's in the middle of the Gobi Desert! With no clothes on!